Preparation of petroleum soluble-oil bases



United States Patent 3,445,388 PREPARATION OF PETROLEUM SOLUBLE- OlL BASES Frederick W. Schuessler, Valparaiso, Ind., assignor to Standard Oil Company, Chicago, 111., a corporation of Indiana No Drawing. Filed Mar. 13, 1967, Ser. No. 622,408 Int. Cl. Cm 1/40; C07c 139/06 US. Cl. 252-33 2 Claims ABSTRACT OF THE DISCLOSURE Petroleum oils, preferably hydrofined dewaxed petroleum oils of suitable viscosity range, are first treated with weak sulfuric acid of 85% to 92% strength, and the weak surfuric acid-treated oil then treated with fuming sulfuric acid to form sulfonic acids which are then neutralized, in situ in the acid-treated oil, with sodium hydroxide to yield soluble-oil bases containing preferentially oil-soluble petroleum sulfonates.

Background of the invention The present invention pertains to improvements in the preparation of petroleum soluble-oil bases, and more particularly pertains to the preparation of petroleum soluble-oil bases in which the preferentially oil-soluble sodium sulfonate used in the soluble-oil composition is formed in situ in the petroleum oil vehicle of the solubleoil composition.

Petroleum soluble-oil compositions are conventionally prepared by admixing with a petroleum oil a preferentially oil-soluble sodium sulfonate obtained in the sulfuric acid treatment of petroleum oils (such sulfonates being referred to in the art as mahogany soaps or mahogany type sulfonates) as the primary emulsifier, secondary emulsifiers, balancing agent, coupling agents and various additives to impart specific properties to the soluble-oil composition.

The soluble-oil base is generally considered to be the preferentially oil-soluble sodium petroleum sulfonate, i.e., mahogany sulfonate, dissolved in the petroleum oil vehicle or carrier oil, which is usually a mildly refined petroleum oil. The mahogany sulfonate is a by-product of the fuming sulfuric acid treating process for the manufacture of white mineral oils. Such sulfonates are removed from the acid-treated oil by extraction, purified, and then adjusted with respect to oil content and alkalinity. The required amount of the purified sulfonate is then blended with the carrier oil to form the soluble-oil base.

Conventional petroleum soluble-oil compositions, and the preparation of the preferentially oil-soluble petroleum sulfonates used in such soluble-oil compositions are well known in the art, as illustrated by US. Patents 2,039,377, 2,243,994, 2,668,146, and many others.

Since the mahogany sulfonate used in the soluble-oil compositions is a by-product in the manufacture of white petroleum oils, the production of soluble-oil bases is intimately linked to the production of white mineral oils. Should, for example, the demand for the former increase at a time when white petroleum oil demand is decreasing, then the supply of mahogany sulfonates may become inadequate.

Summary The process of the present invention comprises treating a petroleum oil, and preferably a dewaxed hydrofined petroleum oil having a Saybolt Universal viscosity at 100 F. in the range of from about 200 seconds to about 230 seconds with from about 3 pounds to about 4 pounds per gallon of charge stock, of a weak sulfuric acid of about 8592% strength, at a temperature of about 120 3,445,388 Patented May 20, 1969 to 145 F., removing the resultant acid sludge, treating the weak sulfuric acid-treated oil with from about 1.2 pounds to about 1.7 pounds per gallon of the original charge stock at a temperature of about to F., of fuming sulfuric acid. The resultant acid sludge is then removed and the sour oil after blowing to remove S0 is neutralized with aqueous sodium hydroxide. The resultant product is a soluble-oil base containing about 10-15 of a preferentially oil-soluble sulfonate in the equivalent weight range of about 400 to 500. To the soluble-oil base oil so obtained there are then added secondary emulsifiers, coupling agents, balancing agents and additives as desired.

The hydrofined petroleum carrier oil employed, may be obtained by any of the hydrofining processes known in the art, for example such hydrofining processes as are described in US. Patents 2,654,696, 2,734,014, 2,904,505, 2,917,448, 3,016,350, and others. Hydrofined petroleum oils having a Saybolt Universal viscosity at 100 F. in the range of from about 200 seconds to about 230 seconds, and at 210 F. in the range of from about 45 seconds to about 47 seconds are preferred.

"ice

Preferred embodiment The following preferred embodiment is illustrative of the present invention:

The carrier oil selected for the purpose of this preferred embodiment was a hydrofined dewaxed petroleum oil having the following inspection:

One hundred gallons of the above hydrofined oil was treated with 350 pounds (3.5 pounds per gallon of charge oil) of sulfuric acid of 89-91% strength at a temperature of 130 F. to reduce the polycyclic aromatics content of the oil. The resultant acid sludge formed, was removed and the acid-treated oil treated with pounds (1.5 pounds per gallon original charge oil) of fuming sulfuric acid, i.e., 104.5% sulfuric acid, at a temperature of 120 F. The acid sludge formed was withdrawn and the acidtreated oil then blown with air to remove S0 The acidtreated oil, essentially free of S0 was then neutralized with 4.2 pounds of aqueous sodium hydroxide to form preferentially oil-soluble petroleum sulfonates in the carrier oil. The sulfonate solution was then heated, while blowing with air, to a temperature of about 240 F. to obtain a bright product. The thus-treated hydrofined oil yielded 81 gallons of a soluble-oil base containing 12.5% preferentially oil-soluble petroleum sulfonates of 470 equivalent weight.

Soluble-oil compositions are formulated with the soluble-oil base of the present invention by incorporating therein desired amounts of a secondary emulsifying agent, such as, soda rosin soap; a dispersing or coupling agent such as, a monohydric aliphatic alcohol, e.g., ethanol, propanol, etc., a polyhydric alcohol, e.g., diethylene glycol, or an alcohol ether, e.g., monobutyl ether; a rust and/ or corrosion inhibitor, such as, ethanolamine, hydroxamic acid derivative, aminonaphthenates, etc.; and a bactericidal agent, such as, a chlorinated phenol, alpha-naphthol, etc. Other materials may be incorporated, if desired, such as extreme pressure agents, antioxidants, etc. The various materials used in the formulation of the finished solubleoil compositions are well known in the art and form no part of the present invention.

Soluble-oils prepared in accordance with the herein described invention are suitable for use as metal working oils, textile oils, insecticidal oils, agricultural spray oils and any other uses for which soluble-oils are usually employed.

Percentages given herein are weight percentages unless otherwise stated.

While the present invention has been described with reference to contain specific preferred embodiments thereof, it is to be understood that it is not limited thereto, except as defined in the appended claims.

I claim: 1. In the preparation of petroleum soluble-oil base compositions containing a preferentially oil-soluble petroleum sodium sulfonates as the primary emulsifier, the improvement comprising:

(a) treating a dewaxed hydrofined petroleum oil having a Saybolt Universal viscosity at 100 F. in the range of from about 200 seconds to about 230 seconds with from about 3 pounds to about 4 pounds, per gallon of said hydrofined petroleum oil, of a weak sulfuric acid of about 85-92% strength at a temperature of from about 120 F. to about 145 F.;

(b) removing the resultant acid sludge formed in (a);

(c) treating the sludge-free weak sulfuric acid-treated oil from step (b) with from about 1.2 pounds to about 1.7 pounds, per gallon of said original hydrofined petroleum oil charge, of fuming sulfuric acid at a temperature of from about 110 F. to about 130 F.;

(d) removing the resultant acid sludge formed in (c);

and

(e) neutralizing the sludge-free fuming sulfuric acidtreated hydrofined petroleum oil from step (d) with .4 sodium hydroxide to form a soluble-oil base consisting essentially of said hydrofined petroleum oil containing from about 10% to about 15% of a preferentially oil-soluble sodium petroleum sulfonate in the equivalent weight range of from about 400 to about 500.

2. The process of claim 1 wherein step (a) a dewaxed hydrofined petroleum oil having a Saybolt Universal viscosity at F. of 215 seconds, is treated with 3.5 pounds of weak sulfuric acid of 89-91% strength at a temperature of 130 F.; in step (c) the weak sulfuric acid-treated hydrofined oil is treated with 1.5 pounds of fuming sulfuric acid at a temperature of F.; and in step (e) the fuming sulfuric acid-treated oil is neutralized with aqueous sodium hydroxide to form a soluble-oil base consisting essentially of said hydrofined petroleum oil containing about 12.5% of preferentially oil-soluble petroleum sodium sulfonate of about 470 equivalent Weight.

References Cited UNITED STATES PATENTS 2,433,646 12/1947 Carter 252-30 2,416,192 2/ 1947 Mertes 25230 DANIEL E. WYMAN, Primary Examiner.

I. VAUGHN, Assistant Examiner.

US. Cl. X.R. 

